Transition to turbulence

Magnetically confined high-temperature plasmas are usually in the state of developed turbulence, the transition to turbulence cannot be studied in these devices. In laboratory-scale low-temperature linear plasma experiments as VINETA.75 the transition to a turbulent state can be studied. Due to the reduced turbulence level, improved confinement regimes in magnetically confined fusion plasmas could be assigned to transitional regimes. In these confinement regimes, the turbulence is often dominated by quasi-coherent modes (as the WCM in I-mode or the QCM in EDA-Hmode), a signature of transitional turbulence. Mechanisms that can be transferred from transitional flows in neutral fluids to magnetized plasmas could then be relevant for understanding the dynamics in these regimes.

 

P. Manz, M. Xu, S.C. Thakur G.R. Tynan 'Nonlinear energy transfer during the transition to drift-interchange turbulence' Plasma Phys. Control. Fusion 53 095001 (2011)

P Manz et al. 'On the phase velocity in between weak and strong plasma edge turbulence'  Plasma Phys. Control. Fusion 60 085002 (2018)